Bumper



Patented Jan. 25, 1927.

UNITED STATES, PATENT orrlcs.

smear. n; SHAW, on NEW YORK, N. Y, assrenon ro UNI ERSALsirooxnnmma'ron,

7 me, or LONG- ISLAND CITY, NEW YORK, A conronarron or YORK.

BUMPER.

Original application filed July 13, 1922, Serial No. 574,638; Dividedand this application filed. August a 26, 1926. Serial No. 131,611. a I

This invention relates to bumpers, socalled, such as are used on motorcars to receive the shock of impact with other cars or obstacles on theroad. This invention relates to such articles which are sometimes calledimpact bars, and more particularly.

. to the type known as spring bar or fiat spring'bar bumpers, in whichthe impact shock is absorbed by the resiliency of the pumper asdistinguished from the type hav-' 'inga rigid bar with a coil spring orsimilar attaching device to absorb the shock of,

impact solely in the attaching means or junction of the device with arigid part of the vehicle.

More particularly this invention relates to improved.v features ofconstruction of the 1 resilient or impact flat spring bar having for itsobjects economy in production, durability, lightening of construction,increase strength, and other features the advantages specification. 1

of which will a pear from the more detailed lso a particular featureincident to the ractice of my invention is the revention-of slipping ofthe flat spring ar forming the outer impact member, so

as'to assure a direct reaction on yielding parts of the bumper by havingthe impact surface held against up or down slipping on [the object withwhich it contacts.

While the construction embodying my invention realizes several or all ofthe objects set forth, a particular embodiment hereinafter specificallydescribed, includes a resilient front impact bar which on its outervertical faceor impact surface his a plurality of narrow bands or stripsslightly offset from the other portion'of the impact face surface, and aparticular feature of this divisional application is the formation ofthe surface of such bands or strips or some of them in amanner to causetwo engaging spring bumperv bars to slip into positive engagement toabsorb the impact by the bars, and to avoid one bar sliding above orbelow the other.

This is accomplished in its preferred form by having narrow borders'at,or near the top and bottom of the impact face, but each in width formingonly a fraction of the total width of the impact surface, and there"fore only a fraction of the total outer surfaceof the spring bar that itis necessary to grind and polish, and as is usual'in the finish ofthis-class of product, 'to nickel-plate.

being left in an unfinished condition and suitably japanned, enameled ortreated in similar manner. As this type of bumper is used on the frontof automobiles and also on the rear, they are constantly exposed to theelements and also exposed to rough usage by impact and scraping onobjects, so that minimizing the amount of surface subjected to a finepolish, my construction has many advantages in durability andretainingits appearance in spite of e 1 yyular usage, with obviouseconomy.

As these bumpers extend either forward or to the rear'beyond the otherparts of the vehicle, for the object of shielding other parts of thevehicle against accidental impact, the overhanging weight of the bumpersubjects the attachment to the rigid "part of the vehicle toconsiderable vertical strain, so that any reduction in weight, withoutsacrifieing the stiffness against im act or without sacrificingresiliency to a sorb impact, relieves the other parts of the vehicle aswell as the means of attachment, in direct proportion to thesaving inweight of the impact bar.

While various modifications may be made in the practice of my inventionasto the methods of attaching the spring impact bar to the front or tothe rear of a car, and the profile ofthe impact surface may be varied asshown and described in the original application of which this is adivision,this divisional application relates particularly to such bumperbars having the bands or stripes in a form preferably as shown-in thedrawings, their faces slightly inclined rearwardly or to the middle,that is in planes converging from the top and bottom edges of the bumperaway from a commonplane and toward the slightly depressed interveningimpact surface. While variations may.

The spring bars 1 and 19-constitutethe main or impact portion of twobumpers with the impact faces 2 and 2 in collision. In Fig. 2 the bordersurfaces or bands 3, on spring bar 1, are slightly-inclined from theupper and lower edge of the bar toward the middle depressed impactsurface 4:. Similarly spring bar 1" has surfaces 3 -3 slightly inclinedtoward its depressed middle surface 4*, so that in the event ofdisalignmefntor non-registering of colliding bumpers even a slightengagement at the .edges will in all cases tend by the/pressure ofimpact, as well as the slight vibration, to

a its resilient parts, soas to'thus' absorb cause the bumpers to slideinto propercontact, that is nest together, or, in other words, to assumerelative position that will assure transmission of the impact of'engagement to be properly received and transmitted by the bumper andcarried through t e shock to the full extent of the resiliency andcushioning effect predetermined by. the design of the bumper, thus grog-1y assuring the proper -,functioning for bar bumpers are intended. L i

In the dotted lines another position of a bumper 1 is shown With itsimpact face depressed at 4., and with the slightly inclined marginalbands 3 --3, showing one of these bands only slightly over-lappingthelower band 3 of spring bar 1, thus illustrating an initial contactwhich will cause the spring bar 1 and 1 to ride into positiveengagement, and thereby assure their proper functioning on collision.

While Fig. 2 shows the marginal bands protruding slightly beyond anintermediate impact surface, it will be understood that the essentialsare to provide suitable inclination of surface. which may be flatonslightly rounded, to assure colliding bumpers moving-into a firmengagement for transmission of the collision shock in a substantiallyhorizontal direction, and that instead 'of only two marginal bands,there may be a different arrangement of impact bands to assure the sameresult. Essentially the, specific form, and others that may equally"serve the purpose, assure acontact of sufficient surface to produce theresults, but without ridges that would mar and indent impact surfaces ofa bumper on collision. The construction thus rovides for a bumper impactprofile t at assures the proper functioning" without a constantscarring, indenting, scratching or otherwise indelibly marring thebumper aspect. This aims for accomplishing the results stated and stillproviding a very durable and. in

every way servicegble 'springlbar bumper. lhe production 0 such bumpersalso involves onlyregular formation by rolling of strip'steel of uniformthickness barsyor at the mostthe formationof abar having the necessaryspring tempering, with a slight deformation of the angleof band surfaceas shown. As illustrated in Fig. 2, the marginal bands on the. impactsurface are slightly above the intermediate depressed impact area, andthe inclination of the bands brings their merging into the depressedsurface close, so that a slight groove, which may in cases beimperceptible, still provides for the proper and economical polishingand nickeling 'of:-the bands, and also their proper functioning.

Having the limited band orstriped al faces in a separate plane, thegrinding which is an initialoperation. to preparethe surface fornickeleplating', means. that only a small fraction of area requiresgrinding I compared with what -was heretofore re quired for perfectlyplain frontj 'bars. In addition, the intervening depressed surfacebetween the bandsconstituting a major portion of; the front of thespring bar, lends itself most advantageousl to any anti-rusting;treatment or to 'finis ing as by enamel,

in anycolors. The grinding and finishing of the bands also assures auniform. de:

marcation between the finish on the bands and the intermediate-surface,thereby permitting facility 'and cheapness' of finish with uniformity inthe-coin leted article.

Bythe. formation 0 the ofiset bands, to

the limit of extent shown and described, the

resiliency of the spring bar is not impaired, but stiffness andresistance to indentation or twisting and bending are increased, whileat the same time this relatively greater ity, as compared with a heavierbar having a plain front. The relatively protruding bands constitute aprotection fonthelfinish such as enameling-applied tothemterinedistiffness results with all the desiredflexibilate surfaces,so that in their use substantial advantage in durability of appearanceand' otherwise, is a practical result ingaddition to the relativelightness and greaterre' si'liency, as well as strengthening,weightfor-weight as. compared with a plain surface bar. I

In operation when used on an automobile, the'iinpact of this improvedbumper nvolves an engagement with any part of anothervehicle wth the,advantage of heldin its contact upon impact instead ofqa'j tenifency' toslip up or down, which latter occurs with a plain surface. When suchbumper engages the rear bumper of anothencar; of similar profile, orhaving longitud nally I handed contact surface, the engaging bandsregister with the respective depressed surfaces of the other bumper,thus-prevent ng a front bumper underrunning the rear bumper'of a car, oroverriding, so that one bumper would strike parts of the vehicle such asgasoline tank or headlights, hable to be seriously damaged. In the caseof more than two slightly fore-set bands, their engagement with theimpact face of the bumper on another car having similar profile, insuresa gripping thatminimizes the of relative vertical movement as c paredwith other forms of my bumper 'in- 'twhich only two offset bands areused.

The section of .the bars as herein described, while conforming to whatmay be generally referred to as a channel section profile, in volves inreality only a very slight depression, that is, a surface-profiling inthe direction of the length of the bar. The offsetting of the edges, orthe longitudinal portions forming the protruding, strips or bands of theim act face, is not such as to constitute a rigid ange that wouldprevent resiliency. In the referred form they rovide borders or band ofsuificient width or stiffness and for the purpose of accommodating thegrinding and polishing without having the tools therefor interfere withthe intermediate surface. Thus as to various objects, simplicity ofmanufacture results with strength ening of the bar but without impairingthe elasticity for the purpose of absorbing the shock and carrying anddistributing the l l 'rain of impact to the desired substantial parts ofthe vehicle, without injury. Like- -wise, protection of radiator and lam's in the front, the tank in the rear, an any of the car proper isassured in addition to relieving all parts of the vehicle of shock.

Spring impact bars heretofore used have been made of plain smooth-face,spring bar stock which is tempered, and to suitably finish the same theentire front side or profile involves grinding of a surface the entirewidth of the front of the bar and also] it will beunderstood that theproduction of spring bars involves tempering, and scale due to heattreatment more or less interferes with grindin necessary to conditionthe surface for p ating. In all of this my construction involves a eatlydiminished surface requiring grin ing, and in practice represents 111the neighborhood of a saving sorb the impact on, the spring of threequarters of the work in finishing the bars as compared with thefinishing and nickel-plating of the entire front surface. Theintermediate surfaces between the bands may be japanned in any color tomatch the finish of the other parts of the car, and in any event lendsitself to a dull and relatively cheap treatment of the surface for itsprotection. The intermediate surfaces are, furthermore, partiallyprotected by. the slightly protruding. bands.

By'providing a cross-section of bumper bar as herein described, thestructural advantages are attained, such as stiffening withoutinterfering with flexibility, also strengthening and stiffening the topvand bottom edges without increasing the weight 7 compared with barshaving a straight front impact surface,atta1ning these advantages inequal strength with a (llIIllIllltlOl'l in weight as compared with a:plain bar.

'In order "that bumpers onniotor cars should effectively absorb theshock of impact,the bumperon a rear of=a car must be engaged by thefront bumper on a following car colliding with it. Uniformity ofheightof bumpers is therefore prescribedand is being more and more generallycomplied with by making the brackets carry the bumpers at the uniformheight. However, original design and equipment are in practice subjectto universal variation of I load which depresses the vehicle springs,and is also subject to variation of tire inflation, {which in road useprecludes exact registration of bumper engagement: This withthe slightvibration and road inequalities will always present a condition ofvariation of an inchor two between the heights of the rear bumper andthe front bumper of a following car. Much of the failure of proper.functioning of bumpers is caused by slidingof the smooth surface ofbumpers, whereby one overrides the other and temporarity therefore theyfail to properly abbar bumper, which also frequently causes thepermanent vertical dislocation of the impact bar at its attachingdevices connecting it with the rigid parts of the vehicle. i

The essentials involved in the features of constructionof thisapplication, serve to assure the proper functioning of colliding springbar bumpers, as .well as to maintain described without departing from myinvention, -what I claim and desire to secure by .LettersPatent is:

l. A spring impact bar for automobile bumpers having aboutthree-quarters or less ofits-impact surface slightly depressed, and aplurality of longitudinal narrow smooth faced hands of impact surfaceprojecting beyond the main surface, one of said projecting bands havingthe surface in a plane slightly inclined toward the depressed surfacearea.

2. An automobile spring bar bumper having an :impact face comprising topand bottom marginal flat faced bands of an aggregate width a quarter 0 tmo e of the total Width of the impact face, an intermediate impactsurface slightly back-set from the surfaces of the bands, the flatsurfaces of said bands being respectively in converging planes slightlyinclined toward the back set intermediate impact .surface.

3. A spring impact/bar for automobile bumpers including a resilient barhaving a plurality of slightly offset bands with fiat impactlsurfacestogether of greater width than the thickness of the bar, each surfacebeing in'a plane slightly inclined toward the middle of the impact faceand with ad' jacent slight depressions of impact surface adapted toengage similar roffset bands of a colliding impact bar, wherebyover-riding of two such engaging bars of like impact face is prevented4. An automobile spring bumper having an impact face com rising aplurality as of longitudinal smooth aced hands of impact surface, and adacenbunhniShed areas of impact face, a predominating surface of eachband being inclined inwardly toward the middle of the bar, wherebyinterengag- 40 ing bumper bars will tend'to maintain their engagementfor the purpose of transmitting I horizontal shock absorption.

5. An automobile spring bumperhaving, a broad thin impact bar, a band orstrip on the impact face of the bar extending longitudinally of thebarand of a breadth A less than a quarter '0 the impact faceof the barand haying the'j face of said band extending downwardly from the topedge slightly inclined toward the body of the. bar, and having asubstantially. symmetrical" band along thebottom edge ofthe bar. I

In testimony whereof, I have, signed my name to this application thisl2' day ofz August, 1926.

SAMUEL HQsI-I AW 1

